London, 1883. 125 Gower Street was once a house of justice, truth, and perspicacity. Now madness, murder, and scandal lurk in its empty halls. It is rumored that its owner—Sidney Grice, London's foremost personal detective—has been driven to the brink of despair. But, as with all good stories, we must begin at the beginning.

When Sidney Grice journeys to Yorkshire to solve a mysterious death, March Middleton, his ward, is left to her own devices in a London swarming with danger and vice. Curiosity, as we know, has a dark edge. So when an intriguing letter leads March to the gates of the palatial Saturn Villa and into the nightmarish world of her long-lost uncle, it could be the beginning of an end for all.